1. Holistic Twig Joins: Optimal XML Pattern Matching Written by: Nicolas Bruno Nick Koudas Divesh Srivastava Presented by: Jose Luna John Bassett

2. What is XML? Extensible Markup Language Tag-based markup language that allows you to share structured information Information is easily transferred across systems

3. XML Example

4. Twigs A twig is simply a subtree Example (ignore numbers for now):

5. What is XQuery? Query language designed to query collections of XML data XQuery is a full-fledged query language, but we are only concerned with ancestor- descendent and parent-child relationships.

6. XQuery Relationships Single line indicates parent-child relationship Double line indicates an ancestor- descendent relationship

7. XQuery Example 1 Query: book[title = ‘XML’ and year = ‘2000’] Associated query tree:

8. XQuery Example 2 Query: book[title = ‘XML’]//author[fn = ‘jane’ AND ln = ‘doe’] Associated query tree:

10. XB-Trees An XB-Tree is simply a B-Tree that is designed to index this XML data using the positional data Indexing using (LeftPos : RightPos) Querying is done just as is done in a regular B-Tree

11. XB-Tree Example

12. Experimental Results

18. Questions? Thank you!